I have a intertherm gas furnace model#mgbb 070 abf c 01 which burns nat gas it won't ignite fan will run in fan position pilot stays lit clicks when t stat is moved but yet won't ignite can't seem too find reset if there is one

The only way to know what is happening is for you to use a volt meter and check whether you have 24 volts at the gas valve. If you do and the pilot light is lit then you need a new gas valve. If not, you may have a bad t-stat or broken or loose wire somewhere. There is a reset on the high limit which is in the same housing as the fan switch. It's a 2"x4" silver (usually) housing where the cover just pops off. It has a rod attached which goes into heat exchanger where it's mounted. The dial inside is where you set the temp for the fan to come on and shut off, and on that same dial is a fixed high-limit switch. Just use a meter and you will figure it out in no time.